EAST RUTHERFORD, N.J. -- Pity the team that opens a half against the Seattle Seahawks.

Super Bowl XLVIII was a competitive fiasco on the first play from scrimmage, when an errant snap to Peyton Manning sailed into the Denver Broncos’ end zone for a safety.

It was a full-scale farce when Seahawks receiver Percy Harvin took the second-half kickoff and romped 87 yards for a touchdown, bloating Seattle’s already eye-popping lead to 29-0 when a busy Stephen Hauschka added the extra point.

Anyone who figured the No. 1 scoring offense powered by Manning, a five-time MVP, might get the upper hand on the NFL’s No. 1 scoring defense was drastically underestimating the ferocity of Seattle’s Legion of Boom.

The Seahawks’ astonishing defense forced four turnovers and absolutely humiliated the Broncos 43-8 at MetLife Stadium, a contest that punched the number 12 in our faces over and over:

--The number of seconds the Seahawks needed to score the fastest points in Super Bowl history: 12.

--The number of seconds Harvin required to get into the end zone on his second-half kickoff return: 12.

--The devoted Pacific Northwest fan base sporting Seahawks blue, which motivates this team into a frenzy: The 12th Man.

“It’s unbelievable -- 12th Man, we did it! We brought the Super Bowl back!” said loquacious cornerback Richard Sherman, who left the field on a cart after injuring his right ankle -- not seriously -- in the fourth quarter. “We love you guys, and we’re on our way!”

They got there, to NFL immortality, by leaving their footprints all over the staggering Broncos. And no one felt the brunt of that pressure more than Manning, who never had a chance to get the highest-scoring offense in NFL history out of park, let alone any gear.

“The turnover on the first play of the game to give them a safety is not the way you want to start a game,” Manning said, in the understatement of the year.

“We wanted to keep the game on the field and keep the score even. We got behind early and never could make a run to catch up. From that standpoint, it was a disadvantage for us and an advantage for them.”

Not since the 1985 Chicago Bears or the 2000 Baltimore Ravens has the NFL seen a defense this forceful. The Seahawks, who specialize in delivering crushing hits that somehow stay legal, rushed their intimidating front seven at Manning relentlessly. The regular season MVP managed to set a Super Bowl record for completions with 34, but the Broncos’ offense largely consisted of mid-range passes that were pitifully futile.

Seattle’s defenders stopped harassing Manning and the Denver passing attack long enough to neutralize running back Knowshon Moreno to the tune of 17 rushing yards.

“When you face a quarterback like (Manning), you better be able to affect him,” Seahawks defensive coordinator Dan Quinn said. “We didn’t talk about the size of hits. We talked about, can we get him off the spot?”

Malcolm Smith certainly did. One of only three linebackers in NFL history to earn the Super Bowl MVP award, Smith returned a first-half Manning interception 69 yards for a touchdown for a 22-0 lead, and recovered a fumble in the second half to further lock down this thing.

If you didn’t know much about Smith before the 2013 season, you’re forgiven: He didn’t have an interception in his first 43 career games.

Since then, he’s come up with interceptions in four of his last five contests, including the playoffs.

Smith is the kind of opportunistic player who personifies a Seahawks group built from the ground up by coach Pete Carroll and general manager John Schneider: gems in the weeds that other teams have overlooked.

This is a team that bolds the word “unheralded”: 21 of the Seahawks' 53 players were undrafted. Many of them were largely ignored coming out of college. Smith, a speedy seventh-round pick who played for Carroll at USC, was asked after the game to recount his 40-yard dash time at the NFL’s Scouting Combine.

“I didn’t get invited to that Combine,” Smith said simply.

Carroll has pounded a simple mantra into his team: “Always Compete.” It’s been a mindset that helped keep a group of proud underdogs ready to pounce.

“We’re a bunch of misfits, in some ways,” said Sherman, a fourth-round pick who takes pride in touting his defense’s back-of-the-pack pedigree. “I think the world learned how complete a team we are, how complete our defense is.”

The kind of statement the Seahawks made on Sunday ensures the world is now abundantly aware of their presence.